what are the appropriate adjectives of time to say about things that happens a few minutes or hours ago i mean things that have happened in the past but not far in time? i heard some people said 'Those names whom i just called just now'. (Does just now means like 5 minutes ago?) some say 'she sang the national anthem just before. now she is singing a patriotic song.' when in fact, that girl had sung the national anthem an hour before she sang another song. other adjectives of time that i know of are 'a moment ago', this morning, shortly after, and this afternoon.

Sebayanpendam - the words you describe are not adjectives, they are adverbs. And the meanings sometimes are relative, not absolute.

"just now" means immediately before this moment in time, but to some people, that can be one minute before, and for others it can be an hour or a day before. It is all in that person's sense of time. The same is true for "recently".
If you want to be precise and absolute, then use expressions like "within the past five minutes".